Recent technological advances in coupling electron microscopy to analytic techniques involving electron-electron interactions have been applied to neurochemistry and neuropathology. Localization of heavy metals was successfully studied at the subcellular level in experimental lead poisoning, cis-platinum treatment, and manganese exposure. Clinically, brain tissue from patients with Alzheimers disease and amyelotrophic lateral sclerosis was studied for increased local concentrations of aluminum, lead, and other toxic metals. Metabolism of endogenous elements, elemental drugs (lithium) and tagged neurotransmitters and receptor ligands is also being studied.